Mariners vs Red Sox Prediction, Odds, Moneyline, Spread & Over/Under for June 18

Odds updated as of 3:11 p.m.

The Boston Red Sox will take on the Seattle Mariners in MLB action on Wednesday.

We've got you covered, in terms of the vital info regarding this matchup before you take a look at the MLB odds and spreads on FanDuel Sportsbook.

Red Sox vs Mariners Game Info

• Boston Red Sox (38-37) vs. Seattle Mariners (37-35)
• Date: Wednesday, June 18, 2025
• Time: 4:10 p.m. ET
• Venue: T-Mobile Park -- Seattle, Washington
• Coverage: MLB Network, ROOT Sports NW, and NESN

Red Sox vs Mariners Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: BOS: (-118) | SEA: (-100)
• Spread: BOS: -1.5 (+155) | SEA: +1.5 (-188)
• Total: 6.5 -- Over: (-118) | Under: (-104)

Red Sox vs Mariners Probable Starting Pitchers

Probable Pitchers: Garrett Crochet (Red Sox) - 6-4, 2.24 ERA vs Luis Castillo (Mariners) - 4-4, 3.29 ERA

This contest's pitching matchup is set, as the Red Sox will send Garrett Crochet (6-4) to the mound, while Luis Castillo (4-4) will answer the bell for the Mariners. When Crochet starts, his team is 7-8-0 against the spread this season. Crochet's team is 7-6 this season when he starts and they are the moneyline favorite. The Mariners have gone 6-8-0 ATS in Castillo's 14 starts with a set spread. The Mariners were named the moneyline underdog for two Castillo starts this season -- they split the games.

Red Sox vs Mariners Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Mariners win (51.2%)

Red Sox vs Mariners Moneyline

• Looking at the moneyline for Red Sox-Mariners, Boston is the favorite at -118, and Seattle is -100 playing at home.

Red Sox vs Mariners Spread

• The Mariners are +1.5 on the run line against the Red Sox. The Mariners are -188 to cover, and the Red Sox are +155.

Red Sox vs Mariners Over/Under

• The over/under for Red Sox-Mariners on June 18 is 6.5. The over is -118, and the under is -104.

Bet on Boston Red Sox vs. Seattle Mariners on FanDuel today!

Red Sox vs Mariners Betting Trends

• The Red Sox have been favorites in 47 games this season and have come away with the win 24 times (51.1%) in those contests.
• This season Boston has come away with a win 20 times in 36 chances when named as a favorite of at least -118 on the moneyline.
• The Red Sox and their opponents have gone over in 34 of their 75 games with a total set by sportsbooks this season.
• The Red Sox are 39-36-0 against the spread in their 75 games with a line set by sportsbooks this season.
• The Mariners have won 52.2% of the games this season they were the underdog on the moneyline (12-11).
• Seattle has an 11-7 record (winning 61.1% of its games) when playing as a moneyline underdog of -100 or longer.
• The Mariners have played in 71 games with an over/under set, and have combined with opponents to go over the total 37 times (37-30-4).
• The Mariners have a 31-40-0 record against the spread this season (covering 43.7% of the time).

Red Sox Player Leaders

• Jarren Duran leads Boston with a slugging percentage of .417, fueled by 31 extra-base hits. He has a .261 batting average and an on-base percentage of .316.
• Among qualifying hitters in MLB, his batting average ranks 69th, his on-base percentage ranks 103rd, and he is 87th in slugging.
• Ceddanne Rafaela has 11 doubles, two triples, six home runs and 14 walks. He's batting .247 and slugging .385 with an on-base percentage of .296.
• Among all qualified, he ranks 96th in batting average, 130th in on-base percentage and 117th in slugging percentage.
• Carlos Narvaez has 53 hits this season and has a slash line of .277/.364/.450.
• Trevor Story is batting .230 with a .275 OBP and 36 RBI for Boston this season.

Mariners Player Leaders

• Cal Raleigh is leading the Mariners with 70 hits. He's batting .266 and slugging .624 with an on-base percentage of .374.
• Including all qualifying hitters in the majors, he is 59th in batting average, 22nd in on-base percentage and third in slugging percentage.
• Julio Rodriguez's .412 slugging percentage paces his team. He has a batting average of .258 with an on-base percentage of .321.
• He is currently 74th in batting average, 94th in on-base percentage and 94th in slugging percentage among all qualifying hitters.
• J.P. Crawford has put up an on-base percentage of .416, a team-best for the Mariners.
• Jorge Polanco is hitting .259 with eight doubles, 11 home runs and 13 walks.

Red Sox vs Mariners Head to Head

• 6/17/2025: 8-0 SEA (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -162, Underdog Moneyline: +136)
• 6/16/2025: 2-0 BOS (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -178, Underdog Moneyline: +150)
• 4/24/2025: 4-3 SEA (Favorite: Red Sox, Spread: -1.5, Total: 8, Favorite Moneyline: -180, Underdog Moneyline: +152)
• 4/23/2025: 8-5 SEA (Favorite: Red Sox, Spread: -1.5, Total: 9.5, Favorite Moneyline: -136, Underdog Moneyline: +116)
• 4/22/2025: 8-3 BOS (Favorite: Red Sox, Spread: -1.5, Total: 9.5, Favorite Moneyline: -122, Underdog Moneyline: +104)
• 7/31/2024: 3-2 BOS (Favorite: Mariners, Spread: -1.5, Total: 9.5, Favorite Moneyline: -112, Underdog Moneyline: -104)
• 7/30/2024: 10-6 SEA (Favorite: Mariners, Spread: -1.5, Total: 10.5, Favorite Moneyline: -118, Underdog Moneyline: -100)
• 7/29/2024: 14-7 BOS (Favorite: Red Sox, Spread: -1.5, Total: 8.5, Favorite Moneyline: -120, Underdog Moneyline: +102)
• 3/31/2024: 5-1 BOS (Favorite: Mariners, Spread: -1.5, Total: 7.5, Favorite Moneyline: -120, Underdog Moneyline: +102)
• 3/30/2024: 4-3 SEA (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -164, Underdog Moneyline: +138)

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